The present invention relates in general to a bandpass filter, and more particularly to a multi-resonator bandpass filter of a type having a series of waveguide resonators positioned along a common longitudinal axis so as to define at least a first resonator and a last resonator, with adjacent resonators being mechanically linked to one another by a common coupling plate of sheet metal which is formed with coupling slots for electrically connecting the resonators, wherein the first resonator and the last resonator are closed by end plates of sheet metal.
Bandpass filters of this type are generally known. They have the drawback that the connection and closure of the individual waveguides require complicated and expensive flange structures. This is especially disadvantageous when considering that these bandpass filters are used in (digital) televisions operating in normal TV bands (f&lt;1 GHz), and thus are very bulky.